Biodiversity is the variation in living organisms, viewed within a given habitat, ecosystem or in the world as a whole. The concept is usually applied to the species diversity, although the notion of genetic biodiversity is applied to the variation in genes within an individual species. While most people think of rainforests as loci of great biodiversity, biomes such as oceans and grasslands are the likely repositories for even greater variation. Retention of diverse biota is important, since intact ecosystems are thought to be essential for provision of ecosystem services to humans, including maintenance of a diverse foodbank, pollination, clean water, flood control, pest control, waste decomposition, biomass energy resources and climate stability. Biodiversity is presently critical since we live in the era of the Mass Holocene Extinction, a period of species loss caused by man, and unrivaled in rate of species loss. Although the number of total species numbers in the tens of millions, most have not yet even been described. The extinction of a species is almost always related to destruction of habitat or man-made pollution.
The Permian period lasted from 290 to 248 million years ago and was the last period of the Paleozoic Era. The distinction between the Paleozoic and the Mesozoic is made at the...
Amphibian ecology and evolutionLast Updated on 2014-07-23 18:38:53
Amphibians are found in ponds, streams, wetlands of all types, under rotten logs, in leaf litter, in trees, underground, even in pools of rain water inside large leaves. However, they are not able to osmoregulate in salt water and, therefore, are not found in the ocean. Although some amphibians defy the rules and thrive in cold or dry conditions, the group reaches its highest diversity and numbers in warm, humid climates.
In the wet tropics, amphibians remain active all year around, but in the temperate zone, winter temperatures cool their bodies, forcing them to become inactive.
In the autumn, environmental cues direct amphibians to find moist, sheltered places like muddy pond bottoms or deep leaf litter to hibernate.
The wood frog (Rana sylvatica) has the most northerly range of any amphibian, crossing the Arctic circle, into the Mackenzie River valley in the Northwest... More »
Brassicaceae: An agri-horticulturally important familyLast Updated on 2014-07-22 17:19:27Brassicaceae (Cruciferae) is an important dicotyledonous, angiospermic (true flowering) plant family with a global distribution. Species belonging to the Brassicaceae are well suited to a wide range of intensive and low input agri-techniques. They are primarily adapted to temperate and sub-tropical climates depending on the species. Brassica species play an important role in global agriculture and horticulture.
The genus Brassica was described by Linneus in 1750 based on B. oleracea. Brassica contains a number of important species and wide genetic diversity. The species are characterized by a wide range of adaptations that have been domesticated into crops including oilseed rape/canola and swede (Brassica napus L.); cabbage, cauliflower; broccoli, brussels sprout (B. oleracea L.); turnip, Chinese cabbage and pak choi (B. rapa L.) and mustards (B. nigra (L.) W.D.J. Koch, B. alba... More »
PinnipedLast Updated on 2014-07-21 17:04:25Pinnipeds ("finned-feet") are are group of marine mammals, that includes seals, sea lions, and walruses. The word pinniped is sometimes treated as a synonym for "seal" since all pinnipeds except for the the sole species of Walrus are seals (sea lions are eared seals).
Kingdom: Animalia (Animals)
Class:------ Mammalia (Mammals)
Order:-------- Carnivora (Carnivores)
Family:-------- Otariidae (Eared seals)
Pinnipeds differ form other marine mammals like whales, dolphins and porpoises in that they do not spend their entire lives in water. Pinnipeds "haul out" onto land and ice to mate, give birth, moult, and rest.
Pinnipeds were agressively hunted until the early twentieth century for their skins, oil, meat and, in the case of... More »
Greater St Lucia Wetland Park, South AfricaLast Updated on 2014-07-10 16:27:07
The Greater St. Lucia Wetland Park (32°06’25’’E to 32°56’46’’E. and 26°51’26’’S to 28°29’07’’S) is a World Heritage Site. There are few comparable protected coastlines within the tropics as pristine as St. Lucia's. The Park is one of the outstanding natural wetland sites of Africa. It lies on a tropical-subtropical interface with a wide range of terrestrial, wetland, estuarine lake, coastal and marine environments, which are scenically beautiful and basically unmodified by people. These include coral reefs, long sandy beaches, coastal dunes, lake systems, swamps, and extensive reed and papyrus wetlands, critical habitat for a range of species from Africa's sea, wetlands and savannas. The interaction of these environments with major floods and coastal storms in the Park's transitional... More »
Wetland protection for reptiles and amphibiansLast Updated on 2014-07-10 16:08:27
Wetlands serve as critical habitat for many species of amphibians and reptiles, collectively known as herpetofauna, or “herps". Their reliance on wetlands makes herps especially vulnerable to the loss and degradation of wetlands; indeed, global population declines in reptiles and amphibians may be related to changes in the quality and availability of wetland habitat.
All amphibians rely on wetlands to some extent. Many species lay gelatinous eggs under water, whereas others, like certain salamanders, lay their eggs on moist land. After hatching, many young amphibians enter an aquatic larval stage, which can last from several days to many months (or even several years, as is the case with the Pacific giant salamander (Dicamptodon tenebrosus). On becoming adults, most amphibians adopt a facultatively terrestrial lifestyle, and may use both wetland and upland... More »
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